This invention relates to 5-substituted-2,4-diaminopyrimidine compounds (hereinafter "2,4-diaminopyrimidines") and compositions containing the same which are useful for controlling agricultural pests such as insects and acarids. Still more particularly, this invention relates to certain 2,4-diaminopyrimidine compounds and compositions, and their use as acaricides, and as insecticides, particularly of the order Lepidoptera such as the tobacco budworm, and Coleoptera, such as the Mexican bean beetle.